package homework;

//力扣622题、设计循环队列（中等）
public class MyCircularQueue {
    public int[] elem;
    public int front;
    public int rear;

    public MyCircularQueue(int k) {
        elem = new int[k + 1];//don't forget to plus 1
    }

    public boolean enQueue(int value) {
        if (isFull()){
            return false;
        }
        elem[rear] = value;
        rear = (rear + 1) % elem.length;
        return true;
    }

    public boolean deQueue() {
        if (isEmpty()){
            return false;
        }
        front = (front + 1) % elem.length;
        return true;
    }

    public int Front() {
        if (isEmpty()){
            return -1;
        }
        return elem[front];
    }

    public int Rear() {
        if (isEmpty()){
            return -1;
        }
        int index = 0;
        if (rear == 0){
            index = elem.length - 1;
        }else {
            index = rear - 1;
        }
        return elem[index];
    }

    public boolean isEmpty() {
        return front == rear;
    }

    public boolean isFull() {
        return (rear + 1) % elem.length == front;
    }

}
